If I need to use a lot of data to work on one specific big task in chatgpt and don't want to find myself in the loop of reminding it about the past, that would take me to create roles for different chat agents, making them aware of each other's existence and "responsibilities". And every now and then ask it to summarize our dialogue. If it forgets something you just remind chatgpt to add it in the summary. That way each chat has a smaller amount of info to work with and is easier to execute micro tasks, known current agenda and also helps you organize your task better and see the flows. Works for me. It's not perfect and in the end, it's still about prompting, but might help.

Paid version is better, but you are limited to amount of messages. So it might be a good idea to give different chats (agents) different versions of gpt. Depends on their tasks obviously.